Electron gun construction



March 25, 1958 L. FRENKEL ELECTRON GUN CONSTRUCTION Filed April 25, 1956 hill/Ill IN V EN TOR LOTHAQ HZENKEL. BY

ATTORNEY.

ELECTRON GUN CONSTRUCTION Lothar Frenkel, San Diego, Calif., assignor to General Dynamics Corporation, Rochester, N. Y., a corporation of Delaware Application April 25, 1956, Serial No. 580,570

1 Claim. (Cl. 313-82) This invention relates generally to cathode ray tubes and more particularly to an electron gun construction for such cathode ray tubes.

Various types of gun constructions are known in which a plurality of substantially cylindrical electrodes and apertured disk electrodes are aligned in spaced apart relation along a generally longitudinal axis of a cathode ray tube. In the prior art devices it has been necessary to mechanically join together a. network of bridging to support the electrodes and also to insulate the electrodes one from the other spacing them at the same time from the glass envelope of the tube. This has previously been accomplished by utilization of wire-like bridging carrying ceramic or glass-like sleeves or utilizing glass or ceramic rods to actually carry or space one element from the other. The conventional gun construction described, entails considerable detail of spot welding, sleeving or melting of insulators and fusing them to metallic parts. The prior art, therefore, required rather detailed and laborious techniques in construction of such electron guns all of which was rather time consuming and required highly skilled personnel in assembly thereof.

These disadvantages are overcome by the present invention. The invention includes an electron gun construction wherein an insulating member of a substantially cylindrical shape may be utilized to selectively encompass and house electrodes in predetermined desired shaped and spaced relationships. It is thereby possible to utilize the services of a relatively unskilled person to assemble the electron gun Within the insulating member and maintain a very high degree of assembly accuracy.

It is an object of this invention to provide an electron gun construction which may be readily assembled by relatively unskilled workers.

It is another object of this invention to provide an electron gun construction which may be easily preformed to desired internal configurations which configurations may be utilized to encompass, carry or house desired elec trodes.

It is another object of this invention to provide an electron gun construction wherein certain of the electrodes may be housed and carried by predetermined configurations therein.

It is another object of this invention to provide an electron gun construction wherein certain of the electrodes may be deposited upon the internal surfaces of a we shaped insulating member.

It is another object of this invention to provide an electron gun construction which may be made integral or conterminous with the cathode ray tube.

It is another object of this invention to provide an nited States Patent electron gun construction whose outer surfaces have a co-eflicient of expansion similar to that of the tube.

Other objects and advantages than those set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

Figure l is a view in cross-section of a portion of a cathode ray tube embodying the invention;

Figure 2 is a view in cross-section of a portion of a cathode ray tube showing an additional embodiment of the present invention.

Referring more particularly to Figure 1, a cathode ray tube 10 having an envelope 11, of any known construction such as glass, ceramic or metal, has positioned therein, at a beam generating portion thereof, an electron gun construction 13. The electron gun construction 13 includes a generally cylindrically shaped insulating member 12 having a substantially annularly shaped cross section. Member 12 may be made of any known insulating material such as glass, ceramic or the like, and may be provided with an outer surface 15 and an inner surface 16. The outer surface 15 of the member 12 may be of a circumference such that the member 12 will fit snugly adjacent the internal diameter of the envelope 11 of the tube 10, or of a circumference such that it may be supported by clips 19 in spaced relation to the envelope 11 as is shown in Figure 1. It should also be understood that thte invention includes other methods of spacing the member 12 from the internal surface of envelope 11 as are known in the art.

It is also within the contemplation of this invention to have member 12 provided with the outer surface 15 of predetermined circumference such as to be conterminous with the tube circumferential dimension, as is shown in Figure 2. In this manner the insulating member 12 may be sealed directly to the tube envelope 11, that is, a glass to glass, or glass to ceramic or metal to glass seal may be effected. Such a construction could utilize in addition, any compatible materials having like co-eflicients of expansion. The internal surface 16 of member 12 may be shaped in any predetermined desired shape to house, for example, any predetermined shaped electrodes 14. The outer periphery of the electrodes 14 will determine the complementary desired configuration of the corresponding inner surface 16 which will house electrodes 14. As is well known in the art, the electrodes 14 may be held in position by use of well known lock rings or retainers 17.

It is also within the purview of this invention to utilize the inner surface 16 as a base for depositing thereon metallic or like coatings 18 to be utilized as accelerating electrodes. Any well known printed circuit technique may be utilized to deposit coating 18 to form desired anodes upon the internal surfaces 16 of member 12. Leads 20, to the deisred electrodes, may be brought through member 12, such as by embedding of conductors therein or utilizing well known conductive paints to form leads 20, and directed to any desired position on or along the tube.

The particular embodiment of the invention illustrated and described herein is illustrative only and the invention includes such other modifications and equivalents as may readily appear to those skilled in the art within the scope of the appended claim.

I claim:

An electron gun construction, including electrodes, for utilization in a cathode ray tube, said gun comprising a acemes e i cylindrical insulating member being unitary with the References Cited in the file of this patent envelope of said cathode ray tube and comprising a sub- UNITED STATES PATENTS stantially unlnterrupted umtary structure, said member having an outer surface, and an inner surface, said outer 2,093,876 Von Ardenne Sept 1937 surface being the outer surface of said cathode ray tube 5 2384322 Gunzel et 1939 envelope, said inner surface being generally cylindrical 16041599 Breeden July 221 1952 shaped with varying diameters to selectively encompass, FOREIGN PATENTS carry and house said electrodes, and said inner surface 1058.848 France Man 19 1954 being formed into a plurality of configurations spaced along said member, said configurations complementing 10 said electrodes. 

